Takimoto Y, Kimura A
Department of Internal Medicine, Hiroshima City Asa Civic Hospital.
Rinsho Ketsueki. 1994 Apr;35(4):364-9.
PDGF is a glycoprotein composed of A and B chains, and induced the expression not only in platelets but also in many types of cells. By stimulation inducing cell proliferation, transcription of the A chain is activated, resulting in an increase in mRNA. By stimulation inducing cell differentiation, the A chain is activated at the post-transcriptional level, and the B chain at the transcriptional level, resulting in an increase in both mRNA. The 5' region of the A chain shows a mosaic pattern of positive and negative regulatory elements, suggesting complicated regulation. Also the fragments of the first intron are bond by 110Kd and 90Kd nuclear proteins and regulate the A chain expression. Mechanisms of regulation of the A and B chain gene expression differ markedly. The role of PDGF was then investigated on the mechanism of myelofibrosis frequently observed in myeloproliferative disorders (MPD). In the chronic phase of MPD PDGF was suggested to be leaked or released from megakaryocytes. In the accelerated and blast phase of CML with fibrosis, PDGF-AB or PDGF-BB was found to be secreated from myeloid blasts. These results suggest the importance of PDGF in the pathogenesis of myelofibrosis associated with MPD.
血小板衍生生长因子（PDGF）是一种由A链和B链组成的糖蛋白，不仅在血小板中表达，也在多种类型的细胞中表达。通过诱导细胞增殖的刺激，A链的转录被激活，导致mRNA增加。通过诱导细胞分化的刺激，A链在转录后水平被激活，B链在转录水平被激活，导致两者的mRNA均增加。A链的5'区域显示出正负调控元件的镶嵌模式，表明存在复杂的调控。此外，第一个内含子的片段与110Kd和90Kd的核蛋白结合并调节A链的表达。A链和B链基因表达的调控机制明显不同。随后研究了PDGF在骨髓增殖性疾病（MPD）中常见的骨髓纤维化机制中的作用。在MPD的慢性期，提示PDGF从巨核细胞中泄漏或释放。在伴有纤维化的慢性粒细胞白血病（CML）的加速期和急变期，发现髓系原始细胞分泌PDGF-AB或PDGF-BB。这些结果表明PDGF在与MPD相关的骨髓纤维化发病机制中的重要性。
